Brush heads for dispensing fluid materials are useful in a variety of applications including but not limited to applying liquid and/or powdered materials to the hair and scalp in the grooming of persons or animals. Such materials may include for example insecticides, medicaments, cleansing agents, conditioners or the like. Various types of fluid dispensing brushes and/or combs intended for such use have been known in the prior art.
An early example of such a brush is shown in U.S. Pat. No. 621,917 to Hippisley. That brush includes hollow bristles communicating directly with a refillable fluid reservoir. The fluid to be dispensed flows from the reservoir and passes through the bristles before being discharged. Similar hollow bristles or teeth are also shown in U.S. Pat. No. 2,626,617 to Sullivan, French Patent No. 1,105,353 and U.S. Pat. No. 4,543,913 to Wilkeson. As the passageways through the bristles or comb teeth are necessarily quite small, they are difficult to form economically and are prone to clogging. Sanitation is also a problem since it is very difficult to thoroughly clean the entire fluid flow path in such devices.
Controlling the flow of the material being dispensed in a simple and economical manner has been another problem not satisfactorily addressed by the prior art. Hippisley '917 appears to provide no flow control at all other than the possibility of selectively orienting the brush for either no flow or flow under the influence of gravity. British Patent No. 342,944 to Crouch et al. discloses providing a valve between the fluid reservoir and the bristles. However, separate valve components like these entail additional components and assembly operations.
U.S. Pat. No. 4,543,913 to Wilkeson shows a liquid dispenser and grooming brush for animals in which only some of the teeth or bristles are formed with internal passages for carrying the fluid. Each of these has a free end provided with a "self-sealing slit" which opens to emit fluid only when downward force is applied to the dispenser, pressing the free ends in contact with the skin of the animal. This arrangement also suffers from a number of drawbacks. As noted above, arrangements involving small passages of significant length are difficult to clean and readily become clogged and unsanitary. While the aforementioned slits provide a degree of flow control, they are unfortunately located close to the tip of each bristle. As such, they are not only prone to clogging but are also subjected to substantial wear which may cause premature failure.